‘Hence the preponderance of rosacea amongst fair skinned, light-eyed people of Celtic origin.’

But doctors are baffled about what causes this to happen and why it tends to strike when people are in their 30s.

Some theories blame a microscopic mite (Demodex folliculorum) found on the skin of sufferers, or a bacterium called H. pylori that is thought to stimulate the blood vessels into over use.

My symptoms were typical — experts talk of a scale that starts with flushing, progressing to persistent redness, then developing spots and papules, then visible blood vessels.

More extreme cases can result in thickened skin, a red swollen nose and eye irritation, but according to Dr Bunting ‘this is rare and much more likely to be in men that women’.

Again, doctors don’t know the reason for this.

The condition is not dangerous to health, but it can be damaging to self-esteem — as Jenny Dyson discovered.

The 40-year-old company director from London has suffered with rosacea for more than a decade and she can pinpoint the exact day it kicked off.

‘I was one month into a new job, my boyfriend had some personal problems and I couldn’t leave the office to support him.’

The next day she woke to find, in her words, ‘pizza face’ and so began a 15-year battle with red, inflamed skin — and its effect on her confidence.

‘At work, in a meeting people would often misread my flushing, thinking I was flustered,’ she says

Her social life suffered, too, when rosacea-induced redness led to ‘men thinking you fancied them’. Her self-esteem was also affected.

The standard treatment is a cream containing the antibiotic metronidazole (brand name Rozex), which works by killing bacteria.

Another option is azeliac acid (such as Finacea gel), a compound found in wheat, rye and barley, which kills bacteria as well as reducing the growth of certain surface skin cells that can block pores and cause spots.

‘Those with more severe or persistent disease may need supplementation with oral antibiotics,’ says Dr Bunting.

These are usually tetracycline, metronidazole or erythromycin.

For those who do not like the thought of long-term use (complaints of thrush abound) doctors may prescribe the drugs as and when needed.

Many people with rosacea try to overload it with skin treatment products, but in fact this is the worst thing you can do, says Dr Bunting.

‘Women are desperate for their skin to look good so they throw everything at it, but deep cleansing, exfoliating products and masks are all stripping processes that can worsen the condition,’ she explains.

Many people with rosacea try to overload it with skin treatment products, but in fact this is the worst thing you can do

‘Rosacea sufferers’ skin is flaky and dry as their skin barrier is weaker, and not so effective at keeping moisture locked in.